1. Field
Embodiments of the present invention relate generally to noise cancellation, and, more particularly, relate to the configuration of a differential drive amplifier and a coil arrangement.
2. Background
A shortcoming of long range and/or alignment insensitive wireless power systems can be the emission of high levels of conducted and radiated noise. For example, some loosely coupled wireless power systems can utilize high voltages and large primary coils, both of which can contribute to noise emission when signals generated via switching are inputs to the system. Such systems can pose electromagnetic interference challenges when the systems operate near other electronic products (e.g., mobile phones, game controllers, media playback devices, etc.).
A portion of the noise generated by these systems is common-mode. Common-mode noise can be attributed to the use of high voltages and unshielded primary windings with considerable surface area. High voltages may be utilized when a system is operating at or near resonance to overcome weak coupling between the primary and secondary coils. The use of large, unshielded primary windings to transmit power over long distances can further expose surrounding areas to the resultant noise.